the construction of housing. Or population in the core city may be declining as people move to the less densely populated suburbs while density on the highway is rapidly rising. In short, there are different densities at work, at home, and in transportation, and different densities day and night. What can be said then about the relationship between population density—or more properly, different kinds of population densities—and various aspects of political and governmental systems? The following discussion will briefly examine six possible relationships: (a) the relationship between population density and political or social stability, (b) the relationship between population size and the interplay of central and subordinate government authority, (c) the relationship between population size and government resources and policy options, (d) the relationship between the dispersal of population and the cost of bureaucratic penetration, (e) the relationship between size and the problems of regional disparity, and (f) the relationship between size and density and the optimal size of government. Density and Political Instability. As of 1960, the following European countries had population densities of more than 100 per square kilometer: Netherlands-342 East Germany-150 Belgium-300 Switzerland-130 West Germany—215 Luxembourg—121 United Kingdom—215 Czechoslovakia—107 Italy-164 Hungary-107 Denmark-106 The following regions in Asia, Africa, and Latin America had populations of more than 100 per square kilometer: Hong Kong-2,891 Lebanon-15 8 Singapore-2,813 Ceylon-151 Mauritius—342 Jamaica—142 Taiwan-295 India-136 Puerto Rico-265 Haiti-126 Japan-252 El Salvador-117 South Korea-250 North Vietnam-103 Trinidad-165 Israel-102 Whether one uses as an index of political instability the amount of violence or revolutions or coups d'etats, or the frequency of changes in government, neither of the above lists of densely populated countries correlates well with any list of politically unstable countries. There are both stable and unstable densely populated countries, and most of the unstable countriesan they are of population growth.